1. Field of the Invention
This invention relates to a method of, and an apparatus for, line testing in a telecommunications network.
2. Related Art
A conventional public telecommunications network comprises a relatively small number of interconnected main switches and a much larger number of local switches, each of which is connected to one or two main switches. The local switches are connected to the terminating lines of the network and the far ends of these lines are connected to terminal equipment, such as telephone instruments 10 located in customers"" premises. The network formed from the main switches and local switches is known as the core network while the network formed from the terminating lines is known variously as the access network or local loop. In this specification, it will be referred to as the access network. In the access- network, each terminating line is formed from a pair of copper wires and, typically, between the local switch and terminal equipment, each terminating line passes through several junctions.
A field engineer working in an access network will sometimes need to check the identity or telephone number of a pair of copper wires. In a typical public telecommunications network, some, but not all, of the local switches have test equipment which is capable of transmitting the calling line identity in speech form to an engineer working on a particular terminating line. An example of a local switch having this facility is described in W087/06421. This causes two problems. Firstly, when an engineer wishes to check the identity of a pair of copper cables, he may not know whether the pair of cables is connected to a local switch which has such test equipment. Secondly, when an engineer wishes to check the identity of a pair of copper cables which are connected to a local switch which does not have such test equipment, it may be difficult or even impossible for the engineer to discover the identity of the pair of copper wires;
According to a first aspect of this invention there is provided a method of line testing in a telecommunications network which comprises a network of switches, said network having a test apparatus connected to one of said switches, said test apparatus having a predefined telephone number, said method comprising the steps of:
dialling the predefined telephone number of said test apparatus from a telephone instrument connected to a telephone line;
routing the call from the user through the network to the test apparatus;
said test apparatus answering the call and retrieving the calling line identity of the line from which the call is made, and
said test apparatus transmitting the calling line identity in speech form to the line from which the call was made.
The present invention provides an easy method for a field engineer to check the identity of a pair of lines in the access network.
According to a second aspect of this invention there is provided, in a telecommunications network comprising a network of switches arranged to make connections between terminating telephone lines connected to at least some of said switches, a test apparatus having a predefined telephone number connected to one of said switches and arranged to receive a call routed to it through said network from one of said terminating lines, said test apparatus comprising:
means for answering a call, said call answering means being arranged to retrieve the calling line identity of the line from which the call is made; and
means for transmitting the calling line identity in speech form to the line from which the call was made.
According to a third aspect of this invention there is provided, in a telecommunications network comprising a network of switches arranged to make connections between terminating telephone lines connected to at least some of said switches, a test apparatus having a predefined telephone number connected to one of said switches and arranged to receive a call routed to it through said network from one of said terminating lines, said test apparatus comprising a computer controlled by a program so as to perform the following operations on receiving a call:
answer the call;
retrieve the calling line identity of the line from which the call was made; and
transmit the calling line identity in speech form to the line from which the call was made.
Some local switches have test equipment which is capable of applying a test tone to a specified pair of copper wires and which can then be used for cable pair identification. Where a local switch has such equipment, an engineer may access it from a terminating line belonging to the switch by dialling the short code for the test equipment. Alternatively, he may access it from any other telephone line by dialling its full code telephone number. However, if the engineer is unable to dial in on one of the terminating lines of the switch and he does not know the full code number of the test equipment, he is faced with the problem of not being able to use the test equipment.
According to a fourth aspect of this invention, there is provided a method of applying a test tone to a terminating line of a telecommunications network which comprises a network of switches, said network including local switches connected to terminating lines, at least some of said local switches being provided with test equipment which is capable of providing a test tone on a specified terminating line, said network having a test apparatus connected to one of said switches, said test apparatus having a predefined telephone number, said method comprising the steps of:
said test apparatus receiving a call routed through said network from a user in which the user specifies a terminating line on which a test tone is required; and
said test apparatus instructing the test equipment of the local switch to which the specified terminating line is connected to provide a test tone on the specified terminating line.
According to a fifth aspect of this invention there is provided, in a telecommunications network comprising a network of switches, said network including local switches connected to terminating lines, at least some of said local switches being provided with test equipment which is capable of providing a test tone on a specified terminating line, a test apparatus having a predefined telephone number connected to one of said local switches and arranged to receive a call routed to it through said network from one of said terminating lines; said test apparatus comprising:
means for receiving a call from a user in which the user specifies a terminating line on which a test tone is required; and
means for instructing the test equipment of a local switch to which the specified terminating line is connected to provide a test tone on the specified terminating line.